Weekly churchgoers are much more likely than non-churchgoers to claim they are "very content" with their personal lives, revealing a direct link between religion and self-reported mental wellness in the United States, a recent study reveals.

According to a recent Gallup study, 67 percent of Americans who attend religious services on a weekly basis are "very satisfied" with their personal lives. 44 percent of Americans who attend church on a weekly or monthly basis responded in this way. 48 percent of those who attend either occasionally or never religious services stated they are very satisfied.

According to Gallup, weekly churchgoers are also more likely to say they are very satisfied with their personal lives than those who earn $100,000 or more per year (61 percent). Last week, the poll was released.

While the data clearly reveal that Americans who regularly attend church have higher favorable emotions on Sundays, it leaves the issue unanswered: what makes Sunday so unique for regular churchgoers? One probable explanation is that religious attendance is highest on Sunday in most religions, as this is the day when regular churchgoers are most likely to mingle with their fellow worshippers.

Other studies back up the link between religiosity and happiness, according to Gallup's Frank Newport. For example, according to a major Gallup report from 2012, very religious Americans "rate their lives more positively, are less likely to have ever been diagnosed with depression, and experience fewer daily negative emotions," and "make much better health choices than those who are not as or not at all religious."

"There is an enduring and very well-substantiated finding of a correlation between individuals' personal religiosity and various measures of wellbeing, happiness and mental (and, in some instances, physical) health," Newport wrote.

The reasons for the link, according to Newport, are several. Some researchers credit religion with providing a "calming, beneficial effect," while others credit the "good impact of being a part of a close-knit religious community that creates connections with other religious individuals."

"Belief in religion may give one a feeling of purpose, a believe that life itself has meaning, and belief in an afterlife can alleviate fear of death," Newport said. "Religious people may feel more in control of their lives, and religious rituals' structure and regularity may have beneficial impacts; research also suggests that expressing gratitude decreases anxiety, and gratitude is a basic component of many religions."

In summary, most Americans, religious and non-religious alike, are happier on weekends than during the week because there is more time for leisure and/or spending time with family and friends. Americans, both secular and religious, report feeling more happy feelings on Saturdays than on Fridays, according to another Gallup report.

Sunday is the one day of the week when the moods of regular churchgoers and non-churchgoers sometimes vary dramatically. To prepare for the start of the workweek, some secular Americans may begin to dread returning to work on Monday or limit their social or leisure activities on Sunday.

The study was conducted among 811 adults from January 3 to 16.